Conventional video conferencing systems include a number of terminals communicating real-time video, audio and/or data (often referred to as duo video) streams over and between various networks, such as packet switched networks and circuit switched networks. Video conferencing terminals typically include a camera, a microphone, a loudspeaker and a screen. The audio stream and video stream from the microphone and camera respectively, is compressed and sent to one or more receiving sites in the video conference. All sites in the conference receive live video and audio from the other sites in the conference, thus enabling real time communication with both visual and acoustic information.
In a video conference, the participants may be located in different parts of a country; in different parts of a continent or even on opposite parts of the world. Even though two users in a video conference are geographically separated by thousands of miles, they experience it as if the other user is in the same room. Hence, the use of telecommunication equipment, such as video conference, liberates us from the limitations of time and space. A user does not need to travel 11 hours from Paris to San Francisco to conduct a meeting. However, the danger is that when we no longer need to worry about travel arrangements, it is easy to forget that the other party to a conference operates in a different time zone.